nitrogen dioxide, no₂(g), is a brown gas produced in high - temperature combustion reactions in air. a…
nitrogen dioxide, no₂(g), is a brown gas produced in high - temperature combustion reactions in air. a portion of the uv - visible spectra of samples of no₂(g) at various partial pressures is shown in the following graph.\na. briefly explain why a spectrophotometer should be set at 400 nm to measure the pressure of no₂(g).\nnote on your ap exam, you will handwrite your responses to free - response questions in a test booklet
Answer
Answer:
At 400 nm, the absorbance of NO₂(g) shows a clear - cut and significant dependence on the partial pressure of NO₂(g). Different partial pressures of NO₂(g) result in distinct absorbance values at this wavelength, which allows for a more accurate and reliable measurement of the pressure of NO₂(g) using the Beer - Lambert law (A = εcl, where A is absorbance, ε is the molar absorptivity, c is the concentration which is related to pressure for gases in a given system, and l is the path length).
Brief Explanations:
The graph shows that absorbance varies with partial pressure at 400 nm. This variation enables pressure measurement via Beer - Lambert law principles.